1. Field of the Invention
This invention relates to a method of controlling mill pacing wherein an extraction pitch of a heating furnace is determined while the progress of rolling is controlled in a rolling equipment wherein a plurality of serial rolling mills are provided downstream of the heating furnace in which a plurality of materials are rested on a furnace hearth integrally moving the materials and which can be successively extracted.
2. Description of the Prior Art
In a rolling equipment for seamless steel pipes, shapes and the like, a multiplicity of materials to be rolled are present in a rolling line consisting of a heating furnace and a plurality of rolling mills. Particularly, as compared with the plate rolling, in the seamless steel pipe rolling, the number of rolling mills under control is numerous and the number of pipes under control is numerous, whereby it has been very difficult to shorten a cycle time. In the aforesaid rolling equipment of the prior art, there exists the techniques of controlling the respective rolling mills and the heating furnace; in each the operation thereof has relied on the experiences and the skill of the operators, whereby it has been impossible to improve the productivity to an ideal extremity.
In addition, as a technique for reference, there is a method of controlling a heating furnace described in Patent Kokai (Laid-Open) No. 127812/79 issued by the Patent Office of Japan. However, this method of controlling contemplates that the relations between the elapsed time and the temperature of piercing are sought for the heating furnace and a piercer to thereby control the furnace temperature of the heating furnace, and; as a result a disadvantage is created that the conditions of the group of mills in a posterior process following that of the piercer cannot be sensed.
The present invention has as its object the provision of a method of controlling a mill pacing in a rolling equipment wherein the operating conditions of a rolling line as a whole is optimized to improve the productivity.